local execute = vim.api.nvim_command
local fn = vim.fn


local install_path = fn.stdpath('data')..'/site/pack/packer/start/packer.nvim'

local function load_plugins()

  local use = require('packer').use
  require('packer').startup(function()
    use 'wbthomason/packer.nvim'       -- Package manager
    use 'nvim-treesitter/nvim-treesitter'
    use 'folke/which-key.nvim'
    use 'tpope/vim-commentary'         -- "gc" to comment visual regions/lines
    use {'nvim-telescope/telescope.nvim', requires = {{'nvim-lua/popup.nvim'}, {'nvim-lua/plenary.nvim'}} }
    use 'folke/tokyonight.nvim'         -- Theme
    use 'windwp/nvim-autopairs'    -- Autopairs
    use 'kyazdani42/nvim-tree.lua' -- File explorer
    use { 'glepnir/galaxyline.nvim', config = function() require'salargalaxyline' end, requires = {'kyazdani42/nvim-web-devicons'} }
    use 'lukas-reineke/indent-blankline.nvim'
    use { 'lewis6991/gitsigns.nvim', requires = {'nvim-lua/plenary.nvim'} }
    use { 'TimUntersberger/neogit', requires = 'nvim-lua/plenary.nvim' }
    use 'neovim/nvim-lspconfig'        -- Collection of configurations for built-in LSP client
    use { 'hrsh7th/nvim-compe', requires = { { 'L3MON4D3/LuaSnip' } } }  -- Autocompletion plugin
    use 'kevinhwang91/nvim-bqf'
    use 'mfussenegger/nvim-dap'
    use 'sheerun/vim-polyglot'
    use 'scalameta/nvim-metals'
  end)
end

_G.load_config = function()

  require('nvim-autopairs').setup()
  require("which-key").setup()
  require("salargalaxyline")

  -- Treesitter
  require("nvim-treesitter.configs").setup({
    playground = { enable = true },
    query_linter = {
      enable = true,
      use_virtual_text = true,
      lint_events = { "BufWrite", "CursorHold" },
    },
    ensure_installed = "maintained",
    highlight = { enable = true },
  })

  -- neogit
  require('neogit').setup({
    integrations = {
      diffview = false
    }
  })

  --Incremental live completion
  vim.o.inccommand = "nosplit"

  --Set highlight on search
  vim.o.hlsearch = false
  vim.o.incsearch = true

  --Make line numbers default
  vim.wo.number = true

  --Do not save when switching buffers
  vim.o.hidden = true

  --Enable mouse mode
  vim.o.mouse = "a"

  -- clipboard
  vim.o.clipboard = 'unnamedplus'

  --Enable break indent
  vim.o.breakindent = true

  --Save undo history
  vim.cmd[[set undofile]]

  --Case insensitive searching UNLESS /C or capital in search
  vim.o.ignorecase = true
  vim.o.smartcase = true

  --Decrease update time
  vim.o.updatetime = 250
  vim.wo.signcolumn="yes"

  --Set colorscheme (order is important here)
  vim.g.tokyonight_style = "night"
  vim.g.tokyonight_italic_functions = true
  vim.o.termguicolors = true
  vim.cmd[[colorscheme tokyonight]]


  --Remap space as leader key
  vim.api.nvim_set_keymap('', '<Space>', '<Nop>', { noremap = true, silent=true})
  vim.g.mapleader = " "
  vim.g.maplocalleader = " "

  --Remap for dealing with word wrap
  vim.api.nvim_set_keymap('n', 'k', "v:count == 0 ? 'gk' : 'k'", { noremap=true, expr = true, silent = true})
  vim.api.nvim_set_keymap('n', 'j', "v:count == 0 ? 'gj' : 'j'", {noremap= true, expr = true, silent = true})

  --Remap escape to leave terminal mode
  vim.api.nvim_set_keymap('t', '<Esc>', [[<c-\><c-n>]], {noremap = true})

  --Add map to enter paste mode
  vim.o.pastetoggle="<F3>"

  --Map blankline
  vim.g.indent_blankline_char = "┊"
  vim.g.indent_blankline_filetype_exclude = { 'help', 'packer' }
  vim.g.indent_blankline_buftype_exclude = { 'terminal', 'nofile'}
  vim.g.indent_blankline_char_highlight = 'LineNr'

  -- Toggle to disable mouse mode and indentlines for easier paste
  ToggleMouse = function()
    if vim.o.mouse == 'a' then
      vim.cmd[[IndentBlanklineDisable]]
      vim.wo.signcolumn='no'
      vim.o.mouse = 'v'
      vim.wo.number = false
      print("Mouse disabled")
    else
      vim.cmd[[IndentBlanklineEnable]]
      vim.wo.signcolumn='yes'
      vim.o.mouse = 'a'
      vim.wo.number = true
      print("Mouse enabled")
    end
  end

  vim.api.nvim_set_keymap('n', '<F10>', '<cmd>lua ToggleMouse()<cr>', { noremap = true })

  -- Telescope
  require('telescope').setup {
    defaults = {
      mappings = {
        i = {
          ["<C-u>"] = false,
          ["<C-d>"] = false,
        },
      },
      generic_sorter =  require'telescope.sorters'.get_fzy_sorter,
      file_sorter =  require'telescope.sorters'.get_fzy_sorter,
    }
  }
  --Add leader shortcuts
  vim.api.nvim_set_keymap('n', '<leader>f', [[<cmd>lua require('telescope.builtin').find_files()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader><space>', [[<cmd>lua require('telescope.builtin').buffers()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>l', [[<cmd>lua require('telescope.builtin').current_buffer_fuzzy_find()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>t', [[<cmd>lua require('telescope.builtin').tags()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>?', [[<cmd>lua require('telescope.builtin').oldfiles()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>sd', [[<cmd>lua require('telescope.builtin').grep_string()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>sp', [[<cmd>lua require('telescope.builtin').live_grep()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>o', [[<cmd>lua require('telescope.builtin').tags{ only_current_buffer = true }<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>gc', [[<cmd>lua require('telescope.builtin').git_commits()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>gb', [[<cmd>lua require('telescope.builtin').git_branches()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>gs', [[<cmd>lua require('telescope.builtin').git_status()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>gp', [[<cmd>lua require('telescope.builtin').git_bcommits()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>m', [[<cmd>lua require('nvim-tree').toggle()<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>ng', [[<cmd>lua require('neogit').open({ kind = "split" })<cr>]], { noremap = true, silent = true})
  vim.api.nvim_set_keymap('n', '<leader>nu', ':PackerUpdate<CR>', { noremap = true, silent = true })

  -- Change preview window location
  vim.g.splitbelow = true

  -- Highlight on yank
  vim.api.nvim_exec([[
    augroup YankHighlight
      autocmd!
      autocmd TextYankPost * silent! lua vim.highlight.on_yank()
    augroup end
  ]], false)

  -- Y yank until the end of line
  vim.api.nvim_set_keymap('n', 'Y', 'y$', { noremap = true})
  --
  -- LSP settings
  local nvim_lsp = require('lspconfig')
  local on_attach = function(_client, bufnr)
    vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')

    local opts = { noremap=true, silent=true }
    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gD', '<Cmd>lua vim.lsp.buf.declaration()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gd', '<Cmd>lua vim.lsp.buf.definition()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'K', '<Cmd>lua vim.lsp.buf.hover()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gm', '<cmd>lua vim.lsp.buf.implementation()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<C-k>', '<cmd>lua vim.lsp.buf.signature_help()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<leader>wa', '<cmd>lua vim.lsp.buf.add_workspace_folder()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<leader>wr', '<cmd>lua vim.lsp.buf.remove_workspace_folder()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<leader>wl', '<cmd>lua print(vim.inspect(vim.lsp.buf.list_workspace_folders()))<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<leader>D', '<cmd>lua vim.lsp.buf.type_definition()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<leader>rn', '<cmd>lua vim.lsp.buf.rename()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gr', '<cmd>lua vim.lsp.buf.references()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<leader>ca', '<cmd>lua vim.lsp.buf.code_action()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<leader>e', '<cmd>lua vim.lsp.diagnostic.show_line_diagnostics()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '[d', '<cmd>lua vim.lsp.diagnostic.goto_prev()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', ']d', '<cmd>lua vim.lsp.diagnostic.goto_next()<CR>', opts)
    vim.api.nvim_buf_set_keymap(bufnr, 'n', '<leader>q', '<cmd>lua vim.lsp.diagnostic.set_loclist()<CR>', opts)
  end

  -- Enable the following language servers
  local servers = { 'jdtls', 'pyright', 'rnix','sourcekit', 'sqlls' }
  for _, lsp in ipairs(servers) do
    nvim_lsp[lsp].setup { on_attach = on_attach }
  end

  -- metals
  vim.opt_global.shortmess:remove("F"):append("c")
  metals_config = require("metals").bare_config
  metals_config.init_options.statusBarProvider = "on"
  vim.cmd [[augroup lsp]]
  vim.cmd [[au!]]
  vim.cmd [[au FileType scala,sbt lua require("metals").initialize_or_attach(metals_config)]]
  vim.cmd [[augroup end]]

  -- Map :Format to vim.lsp.buf.formatting()
  vim.cmd([[ command! Format execute 'lua vim.lsp.buf.formatting()' ]])

  -- Set completeopt to have a better completion experience
  vim.o.completeopt="menuone,noinsert"

  -- Compe setup
  require'compe'.setup {
    enabled = true;
    autocomplete = true;
    debug = false;
    min_length = 1;
    preselect = 'enable';
    throttle_time = 80;
    source_timeout = 200;
    incomplete_delay = 400;
    max_abbr_width = 100;
    max_kind_width = 100;
    max_menu_width = 100;
    documentation = true;

    source = {
      path = true;
      nvim_lsp = {
        priority = 1000,
        filetypes = { "scala", "sbt", "java" },
      },
      nvim_lua = true,
      buffer = true,
      luasnip = true,
    };
  }

  local t = function(str)
    return vim.api.nvim_replace_termcodes(str, true, true, true)
  end

  local check_back_space = function()
      local col = vim.fn.col('.') - 1
      if col == 0 or vim.fn.getline('.'):sub(col, col):match('%s') then
          return true
      else
          return false
      end
  end

  -- Use (s-)tab to:
  --- move to prev/next item in completion menuone
  --- jump to prev/next snippet's placeholder
  _G.tab_complete = function()
    if vim.fn.pumvisible() == 1 then
      return t "<C-n>"
    elseif check_back_space() then
      return t "<Tab>"
    else
      return vim.fn['compe#complete']()
    end
  end
  _G.s_tab_complete = function()
    if vim.fn.pumvisible() == 1 then
      return t "<C-p>"
    else
      return t "<S-Tab>"
    end
  end

  vim.api.nvim_set_keymap("i", "<Tab>", "v:lua.tab_complete()", {expr = true})
  vim.api.nvim_set_keymap("s", "<Tab>", "v:lua.tab_complete()", {expr = true})
  vim.api.nvim_set_keymap("i", "<S-Tab>", "v:lua.s_tab_complete()", {expr = true})
  vim.api.nvim_set_keymap("s", "<S-Tab>", "v:lua.s_tab_complete()", {expr = true})

end

if fn.isdirectory(install_path) == 0 then
  fn.system({'git', 'clone', 'https://github.com/wbthomason/packer.nvim', install_path})
  load_plugins()
  require('packer').sync()
  vim.cmd 'autocmd User PackerComplete ++once lua load_config()'
else
  load_plugins()
  _G.load_config()
end